All, thanks for your helpful remarks. Especially the SWATH hulls are an interesting lead.
These hulls seem to be sailing at larger than hull speed without having to be in planing mode.
This is especially clear if you look at a you tube video's
If you look at the wave patterns behind the stern, it looks like the wake pattern of a fast-planing dinghy, except that there is no planing surface.
What seems to be the case here is that the submerged buoyancy (for this vessel it is a central submerged shark-like structure) does not make a wave pattern, and
only the surface piercing elements that have a sharp trailing edge leave a wake in the shape of a planing ship.
To me this suggests that the stern wake pattern is minimized by having a narrow wake.
For those of you that are familiar with aerodynamics: this resembles the Kutta condition for an airfoil. The Kutta condition implies the requirement to have SHARP trailing edge at at airfoil, this ensures that the pressure stagnation point at the airfoil rear has a FIXED position; this ensures smooth flow off the wing at both top and bottom of the airfoil.
Translating what this means for a ship: at the stern of most ships there is not a sharp line where the Kutta condition is satisfied. Rather, it is a broad stern that promotes the formation of a wide and unstable wake, with clearly a high wave resistance. Often, only the rudder trailing edge approaches a sharp line, and the rest of the stern does not.
Now for the SWATH vessel, the sides (these look like ultra-thin catamaran legs), the training edge is indeed a sharp line that resembles the trailing edge of an airfoil, hence kutta condition seems to be satisfied.
This video demonstrates the benefit of the SWATH hull for creating comfortable conditions in rough weather. Something that would be valued by many sailors.
Let me rephrase my original question.
Can a SWATH type hull be used to design a sailing boat that can sail at larger-than-hullspeed conditions?
